Gas burner system



Oct; 1, 1946. J. MOORHEAD GAS BURNER SYSTEM 7 Filed Sept. 29, 1944 2 Sheets-Sheet l FIG / F'IG.3.

Oct. 1, 1946. J. o. NIIOORH.EAD 2,408,673

G AS BURNER SYSTEM Filed Sept. 29, 1944 .2 Sheets-Sheet 2 Patented Oct. 1, 1946 GAS BURNER SYSTEM John 0. Moorhead, Attleboro, Mass, assignor to Metals and Controls Corporation, Attleboro, Mass, a corporation of Massachusetts Application September 29, 1944, Serial No. 556,348

9 Claims.

This invention relates to a gas burner system Q scribed in which a pilot is electrically ignited after a time delay. Other objects will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the ele ments and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which are illustrated several of various possible embodimerits of the invention:

Fig. 1 is a diagram of the system partially in section;

Fig, 2 is a section on an enlarged scale taken on the line 2-2 in Fig. 1;

Fig. 3 is a section through a gas valve shown in Fig. 1;

Fig. 4 is a diagram of an alternative form of and includes a diaphragm l3 which separates compartments l5 and I1. The compartments are connected by a by-pass IS. The flow of gas to pipe 5 is controlled by the bleed H in known manner. Thus, when bleed II is closed the pressure on both sides of diaphragm I3 is the same 'since by-pa ss I9 connects compartments [5 and [1. Opening bleed l I lowers the pressure in compartment l1 since gas is withdrawn therefrom faster than it can be replaced through by-pass IS. The pressure in compartment l5 now being greater moves diaphragm l3 to admit gas to pipe 5. A shaft 2| is mounted on the diaphragm l3 and projects through an opening 23 in the case. The outer end of shaft 2| abuts contact arm 25. Arm 25 is pivotally mounted at 21 and carries on its opposite end contact 29. Contact 29 cooperates with fixed contact 3i mounted on the exterior of valve 1.

A gas valve 33 is connected to bleed H at one side and at the other side to line 35. Line 35 is also connected to a gas pilot 31. Valve 33 is shown .in detailin Fig. -3. It is controlled by a snap-acting thermostatic disc 39, such as shown in Spencer Patent 1,448,240 which, when it snaps to its opposite position of concavity shown in dotted lines in Fig. 3, moves valve member Ill from its solid line position to its dotted line position away from seat 43. Shaft 45 which carries valve M is abutted at its opposite end by spring 41 which normally keeps the valve seated on 43.

Spring 41 is designed so that it is overcome by transmit heat thereto. Heater 5| is connected to terminals 53 and 55.

Pilot 31 includes a tubev 51 made of an electrical insulating material, such as soap-stone, which contains a spiral groove 59. A heater BI is located in this spiral groove and is connected to terminals 63 and 65. A metal tube 51 is located within the soap-stone tube. Ports are bored in this metal tube to allow the gas to seep around the heater 6|. Located below the tube 61 is a thermostatic disc 69 similar to disc 39. Disc 68 is mounted in a chamber 1| which is attached to tube 61. Chamber 1| loosely holds the edges of. disc 69 leaving the central portion free to snap from one position of concavity to an oppositely concave position.

Mounted on the center of disc 69 is a shaft 13 which carries a shut-off valve 15. Valve 15 seats on connecting member 11 attached to chamber 1! and tube 35. Disc 59 is located so that when it ,is in its Fig. 2 position it seats valve 15 against 'member 11, but when it snaps to its opposite. p0.- siticn of concavity disc 69 moves valve 15 away from its seat. An opening 19is formed in disc 69 to permit gas fiow into the tube 61. g

Electrical lc'onnectionsyare made froma main 3 electrical circuit BI, 83 to terminal 21, fixed contact 3|, and terminals 53, 55, G3 and 65 as shown in Fig. 1. A suitable room thermostat 85 and a time switch 81, diagrammatically illustrated in Fig. 1, and constituting demand means, are desirably included.

The operation of the device is as follows: Assuming that thermostatic switch 85 and time switch 81 are closed, a circuit is made to terminals 21, contacts 29 and 3|, terminals 53 and 55, and terminals 53 and 55. No gas is admitted to pipes 3 and 5 through the diaphragm valve since the bleed II is closed. As soon as the current between terminals 53 and 55 has, by means of heater 5|, heated disc 39 sufliciently so that the disc snaps to its dotted line position in Fig. 3, valve 4| opens against the bias of spring 41 and gas is admitted from pipe I I to pipe 35.

At the same time disc 59 has been heated by heater BI and disc 69 likewise snaps thereby opening valve 15. Gas is thereby admitted by bleed II and pipe 35 to pilot 31. Here the gas difiuses around heater BI through the ports in tube 61 and is thereby ignited. As soon as such ignition takes place the flame is drawn by its own suction out of contact with heater BI and the pilot is ignited. Admitting gas to bleed I I, tube 35 and pilot 31 opens the diaphragm valve 1 and passes as to main burner I as described above. This is ignited by pilot 31.

When the diaphragm I3 of valve 1 moves in response to gas passing to bleed II and pilot 31, the circuit between terminal 21 and terminal 3| is broken by the movement of arm 25 which separates contacts 29 and 3|. These contacts remain separated as long as gas passes to pilot 31 and therefore to burner I. The separation of contacts 29 and 3I breaks the circuit to terminals 63 and 65 so that no more current passes to heater BI. Disc 69, however, is maintained in its hot position by conduction of heat from the pilot flame by means of tube 61. Terminals 53 and 55 remain in the circuit so that heater 5| keeps disc 39 in its dotted line position (Fig. 3). The time delays should be matched to give best performance.

Assume now that either thermostatic switch 85 or time switch 81 opens. This breaks the circuit and no further current passes to terminals 53 and 55, Disc 39 thereupon cools, snaps to its solid line position (Fig. 3) allowing spring 41 to close valve 4|. This prevents the passage of gas to pilot 31 and the diaphragm valve thereupon cuts off the flow of gas to burner I. Thermal disc 69 in pilot 31 cools and closes valve 15. This takes place after diaphragm valve I has closed. Closing of the diaphragm valve automatically moves arm 25 to bring contacts 29 and 3| together again and the device is ready to repeat the operation described.

During the operation of burner I it will be noted that the pilot 31 is constantly burning to relight the burner I if for any cause it goes out. If pilot 31 should go out disc 69 will thereupon cool, snap to the position shown in Fig. 2 and thereby close the bleed circuit to pilot 31. This will cause the diaphragm valve 1 to close cutting oil gas to burner I. If switches 85 and 81 are closed at this time the device will re-cycle, first lighting pilot 31 and thereby lighting burner I. Until this occurs, however, the escape of gas is prevented since the gas supply to burner I is shut off until pilot 31 lights.

It will be noted that heater wire 6| is out of the gas current. This is advantageous since the gas flow cools the wire and makes it more diiicult to ignite the gas. After ignition of pilot 31 the wire is out of the gas flame and is therefore not subjected to the destructive action of the high temperature of the gas flame. Heater 5| can therefore be a Nichrome wire rather than platinum wire previously employed in electrically ignited gas pilots.

Gas valve 33 has been described as a disc and heater gas valve, but in lieu thereof a gas solenoid valve may be substituted. The disc and heater valve is preferred since the time delay thereby obtained avoids danger of gas flashing back if the valve is accidentally stuck. It will be noted that the present control system cuts oil current to the heater 6| as soon as the pilot 31 lights. This adds to the life of heater wire 6|.

An alternative form of the invention is shown in Figs. 4 and 5. This embodiment is similar to the Figs. 1-3 embodiment but a gas line 89 is taken from the main gas supply pipe 9 ahead of regulator valve 1. Line 89 directly connects gas valve 33 to the gas supply and a pilot line 9| is taken off the opposite side of valve 33 to feed a pilot 93 of the usual type. A bleed 95 is taken from diaphragm valve 1 and is connected to a valve 91.

Valve 91 is a thermostatically operated gas control valve including a shut-oil valve member 99 (see Fig. 5) which seats against the tube connection IOI. Valve 99 is carried by shaft I03, the other end of which is mounted on the center of a snap-acting thermostatic disc I05. Disc I05 is similar in its operation to discs 39 and 89. Disc I05 is shown in its hot position in Fig. 5; it will be noted that valve 99 has been moved away from its seat. Disc I05 is mounted in a chamber I01. A thermal conducting finger I09 is at tached to this chamber and projects outwardly and into heat conducting relationship with the pilot 93, and may contact it (as shown) or finger I09 may extend into the pilot flame. Tube IOI carries a burner port III the end of which is located adjacent to pilot 93. A heater Wire H3 is close to flash tube II5, attached to the end of pilot 93.

The operation of the Figs. 4-5 device is as follows: Assuming that switches and 81 close, a circuit is made through heater H3, contact 3|. contact 29 and terminal 21, and likewise between terminals 53 and 55. Heaters H3 and 5| thereupon begin to heat and shortly disc 39 will snap, opening valve 4|. This permits gas to flow to pilot 93. Heater II3 thereupon ignites pilot 93 through the diffusion of gas through flash tube H5. The heat from pilot 93 is transmitted by tube 9| to finger I09 and causes disc I05 to snap to its Fig. 5 position. This permits gas to pass from bleed 95. This gas is ignited by pilot 93.

Opening of bleed 95 operates the diaphragm valve 1 to admit gas to burner l which is ignited by pilot 93. Operation of diaphragm valve 1 breaks the circuit to heater II 3 by separating contacts 29 and 3|. Terminals 53 and 55, however, remain in the circuit and current passes through heater 5| until either switch 85 or 81 opens.

If pilot 93 is accidentally extinguished, it will be reignited by burner III or the flow of heat to disc I05 through finger I09 will stop and disc I05 will snap from its Fig. 5 position and close valve 99. This shuts off the bleed from diaphragm valve 1 thereby shutting oil the flow of gas to burner I. The device thereupon recycles, lighting pilot 93 as described above.

If switch 85 or switch 81 opens this cuts oi the flow of current to heater disc 39 cools and snapsto its opposite position permitting spring 41 to close valve 4|. This cuts off pilot 93, disc I05 cools as described above, valve 99 closes, cutting off bleed 95 and this closes diaphragm valve 1 shutting oi the gas to burner l. The device is thereupon ready to recycle when switches 85 and 81 are closed.

It will be noted that in both embodiments of the invention, the breaking of the electrical circuit closes ofi both the pilot and the main burner, thus preventing the escape of gas. This is a desirable safety feature.

It will be clear that the gas burner system disclosed may be varied in other ways in which the heater wire which ignites the pilot, is physically out of the pilot flame but is adjacent thereto so that gas admitted to the pilot will be ignited by the electrical heater but the flame will flash out of contact with the heater upon ignition.

In addition it will be noted that in the above embodiments the heater which ignites the pilot is turned off after it has accomplished its function. This conserves both electrical current and the heater wire itself. Also the pilot is turned off when the main burner is not operating, thereby saving gas.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A gas burner pilot system comprising a main burner and a pilot burner means, a diaphragmcontrolled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragm of said valve, the pilot burner means including a connection to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides of the diaphragm, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner means, a thermostatically controlled shut-off valve controlling at least some flow of gas supply from the diaphragm valve to the pilot burner means, pilot heater ignition means operatively associated with the pilot burner means, but outside of the pilot flame, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means.

2. A gas burner pilot system comprising a main burner and a pilot burner means, a diaphragmcontrolled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragm of said valve, the pilot burner means including a connection to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides of the diaphragm, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner means, a thermostatically controlled shut-off valve controlling at least some flow of gas supply from the diaphragm valve to the pilot burner means, pilot heater ignition means operatively associated wlth'the pilot burner means, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means.

3. A gas burner pilot system comprising a main burner and a pilot burner' means, a diaphragm-controlled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragm of said valve, the pilot burner means including a connection to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides of the diaphragm, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner means, a thermostatically controlled shut-ofi valve controlling at least some flow of gas supply from the diaphragm valve to the pilot burner means, pilot heater ignition means operatively associated with the pilot burner means but outside of the pilot flame, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, means for transmitting heat from the pilot burner means to said shut-off valve, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means.

4. A gas burner pilot system comprising a main burner and a pilot burner means, a diaphragmcontrolled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragmof said valve, the pilot burner means including a connection to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides of the diaphragm, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner means, a thermostatically controlled shut-oflf valve controlling at least some flow of gas supply from the diaphragm valve to the pilot burner means, pilot heater ignition means operatively associated with the pilot bumer means but outside of the pilot flame, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both 01 said heaters, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means, one of the thermostatic controls for the pilot burner means being in heat conductive relation to the flame of the pilot burner means to maintain the pilot burner valve open only so long as the pilot burner means carries a flame.

5. A gas burner pilot system comprising a main burner and a pilot burner, a diaphragm-controlled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragm of said valve, the pilot burner including a connection to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides 01E the diaphragm, a thermostatically controlled gas valv controlling the gas supply to the pilot burner, a thermostatically controlled shut-off valve also controlling flow of gas supply from the diaphragm valve to the pilot burner, pilot heater ignition means operatively associated with the pilot burner but outside of the pilot flame, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said'heaters, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater means independently of the other heater means, the thermostatically controlled shutoff valve being in heat conductive relation to the flame of the pilot burner to maintain the shut-ofi valve open only so long as the pilot burner carries a flame.

6. A gas burner pilot system comprising a main burner and a pilot burner, a diaphragm-controlled regulator valve controlling a supply of gas to the main burner, the gas being fed to one side of the diaphragm of said valve, a thermostatically controlled bleed line controlling said regulator valve, the bleed line being connected to the opposite side of the diaphragm of said valve, a connecting passage between the opposite sides of the diaphragm, a thermostatically controlled gas valve controlling the gas supply to the pilot burner, pilot heater ignition means operatively associated with the pilot lourner but outside of the pilot flame, an electric heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to diaphragm movement of said diaphragm valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means, the thermostatically controlled bleed line being in heat conductive relation to the 'means, pilot heater ignition means operatively associated with the pilot burner means but outside of the pilot flame, a heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to movement of said regulator valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means.

8. A gas burner pilot system comprising a main burner and a pilot burner, a regulator valve controlling a supply of gas to the main burner, the pilot burner including control means controlling said regulator valve, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner, a thermostatically controlled shut-off valve controlling at least some flow of gas supplyfrom said regulator valve to the pilot burner, pilot heater ignition means comprising a heater located within the pilot burner but outside of the pilot flame, a heater controlling the thermostatically controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to movement of said regulator valve adapted to open the circuit only to the pilot heater ignition means independently of the other heater means.

9. A gas burner pilot system comprising a main burner and a pilot burner, a regulator valve controlling a supply of gas to the main burner, the pilot burner including control means controlling said regulator valve, a thermostatically controlled gas valve controlling at least part of the gas supply to the pilot burner, a thermostat ically controlled shut-off valve controlling at least some flow of gas supply from said regulator valve to the pilot burner, said pilot burner having a passage-way for gas, the walls of said passageway having at least one port therein, an electric heater for igniting said pilot burner located out of said passage-way but adjacent to said port, a heater controlling the thermostatical- 1y controlled gas valve, circuit means including demand means arranged to control both of said heaters, and a switch responsive to movement of said regulator valve adapted to open the circuit only to the pilot ignition heater independently of the other heater.

JOHN O. MOORHEAD. 

